Field observations on individuals from an unusually dense intertidal population of Ocenebra lurida (Middendorif, 1849) revealed several interesting features about the feeding biology of this rather enigmatic predatory neogastropod. (1) Unlike the more common drilling gastropods in the northeastern Pacific, O. lurida preyed most heavily upon limpets: of 231 feeding observations, 55.0% were limpets (Lottia pelta [Collisella pelta], L. strigatella [C. strigatella], and Tectura scutum [Notoacmea scutum]), 42.0% were barnacles (Balanus glandula, B. crenalus, Semibalanus cariosus, and Chthamalus dalli), 2.2% were mussels (Mytilus edolis), and 0.8% were other prey (Calliostoma ligatum and Spirorbis sp.). (2) The mean size of both limpets and barnacles consumed increased with increasing predator size, although this increase was not significant statistically for barnacles. (3) Over a broad range of predator size, both the mean and the maximum shell length of eaten T. scutum exceeded that of L. pelta (by 7 and 5 mm respectively). This observed difference in maximum shell length corresponded rather closely to that expected if the limit to vulnerability were determined by shell thickness, but it could also have resulted from differences in food value between the two species. (4) As observed for the Australian Dicathais aegrota, the distribution of drill sites on limpet shells was distinctly nonrandom: 85% of 124 drill holes were located in the posterior half of the limpet’s shell and 95% were medial to the pedal retractor muscle scar. (5) When eating limpets, O. lurida tended to consume the gonad first, followed by the digestive gland and then the foot, but the foot was eaten only when the shell length of the limpets was less than that of O. lurida. (6) When feeding on the barnacle Semibalanus carlosus, O. lurida attacked lateral wall plates almost exclusively (37 of 38) and nearly half of the attacks (46%) occurred at the sutures between adjacent plates. Because sutures form only about 15% of the periphery, these results suggest a preference for sutural attack. (7) Patterns in the degree of completion of unfinished drill holes suggest that larger O. lurida attack limpets sooner after tidal immersion than smaller ones